Method of fireproofing wood.



ices-45' excellent fireproofiug ,-medium for woo a UNITED STArn-s deference arena- MET/HOD oF FlR'E-PaooFiNc woos.

srncrmcnrxon forming part of Lertersfatent No.

I Application filed June 25,1900. Se ial 110, 21,468

T0 aZZ whom it may concern-.-

Be it known that I, KARL RfIOKER, Ph. D, and chemist, a subject of the Emperor of Germany, and a resident of Zernsdorf, near Konigswusterhausen, in the Empire of Germany, have invented certain new and useful 1111- provements in Methods of Rendering Wood, Paper, and Such Like Material Fireproof, of which the following is a specification.

It is known that ammonium sulfate is an P per, fabrics, and other substances." t is also known, however, that ammonium sulfate is readily soluble and is-dissolved even by damp atmosphere alone. .This bad quality restricts the use of this salt to such an extent that it must be excluded from the category of prac-' ticable available fireproofing mediums. As it goes into solution in damp atmosphere, it affects not only the impregnated wood, fabric, or the like, but accomplishes to the greatest extent destruction ofeverything that comes in contact with the impregnated substance, such as metallic mountings, clothing,

&c. In order to obviate this objectionableproperty of ammonium sulfate-namely, its

. ready solubility-the same is, according to the present iuventiomused in chemicalcombination with ametallic sulfate, producing a metallic ammonium sulfate-such, for example,.as magn esium a uium sulfate,

. en l The several components must, according to the invention, be mixed in theexact proportions in which they occur in the above illustrative double sulfate. For the formation of this magnesium ammonium sulfate, by way of example, the following equation-williserve in which/the numbers above the-"individual components designate their molecular weights. From this it follows that ainmonium 'I refer to sulfate and magnesium sulfate produce the 691,812, dated January :28, 1902.

(No specimens.)

magnesium ammonium sulfate only in the proportion 132224.61 :1 :1,S6, and these proportions must be used in order to obtain a comwould be unconditionally surplusage' in so far as the undesirable properties of this substance had any effect, and this couldonly bemercially practical impregnating mixture. A surplus of one of the two componentparts neutralized in the form of ammonium metal lic sulfate. If ammonium sulfate isprovided in greater proportion than the ratio requires, just so far is the product made undesirable by the bad property of its ready'solubility,

which the double sulfate does not take up If we have more of the magnesium sulfate, v, thenthis excess will have its efiect to just 1 that extent to which the increased proportion is provided. The presence of an excess of magnesium sulfate minimum, first,because its fireproofing ca" pacity is, so to speak, nil, and, second, because the combination, like all magnesium salts, has the propertyunder high temperature of producing a strongly-iucandescing oxid, which can in the event damage, owing to its remaining incandescent for a long-time and spreading the firebythe dropping of the embers.

It is to be understood that I do not limit myself to the described magnesium ammoniumsulfate, for obviously instead of magnesium sulfate in the formation of the double salt one of the sulfatesof zinc, iron, cobalt, nickehor copper may be employed and when used in'like ratio will fate selected as anexample. Therefore when magnesium ammonium sulfate in the claims I intend to include all the double sulfates that are chemical the purpose intended. These several metal lic sulfates would be used in the following proportions to one part of ammonium sulfate: magnsium sulfate, 1.86 parts; zinc sulfate, 2.18 parts; iron sulfate, 2.10 parts; cobalt sulfate, 2.13 parts; nickel sulfate, 2.13 parts; copper sulfate, 2.16 parts.

In impregnating wood especially boracic acid may be added to the double salt, or after the wood has been impregnated with the double salt it may be subsequently treated Boracic acid forms under with horacic acid.

is to be restricted to a j of a fire cause produce metallic am mouium sulfate equivalent to the double sulequivalents for being employed to give with the salts a cubic contents of one cubic meter; but if in the formation of the impregnating fluid the finished metallic ammonium sulfateas, for example, magnesium-ammonium sulfateis to be used immediately, then onetakes from'the latter for one cubic meter of impregnating fluid two hundred and fifty kilograms and fifty kilograms boracic acid. The wood is impregnated with the solution thus made. One can use for this purpose one of the known mechanical impregnating processes. For the better understanding there is here given an example of how one handles the wood with the impregnating fluid thus produced.

The impregnating fluid is warmed up to 60 to 98 centigrade and the wood is impregnated with the same. For this purpose one can introduce the wood into an air-tight closable vessel, which is evacuated, together with the wood, and after this has taken place the fluid,

warmedto 60? to 70.", is next permitted to enter the vessel, is then warmed to about 98 cent-igrade, and is permitted to have its effeet upon the wood for about three to twentyfour hours, during which time the temperature must remain even. The pressure in the vessel is now raised for'a time up to six atmospheres, while the temperature is continu-' ally held to about 98 centigrade. After the expiration of this time the fluid is drawn 0E and the wood withdrawn from the vessel and ried.-

Having thus described my invention, the following is what I claim as new therein, and desire to secure by Letters Patent:

l. The process of impregnatingwood, paper, fabric, and the like, which consists in evacuating the pores of the material to be impregnated, applying to said material the herein-described solution of magnesium ammonium sulfate (NH,) SO,.MgSO,.6H O+H O.) at a temperature of about centigrade, then raising the temperature of the said metallicammonium-sulfate solution to about the boiling temperature of water, permitting the metallic-ammonium-sulfate solutionto affect the material for asuitable time, according to the quality of the material being treated, and finally forcing the metallic-ammouium-sulfate, solution into the pores of the material under treatment, by heavy pressure.

2. The process of impregnating wood, paper, fabrics, and the like, which consists in heating a solution of magnesium ammonium sulfate to a temperature of about 60 centigrade, supplying it to the previously-evacuated material to be treated, raising the temperature of the magnesium-ammonium-sulfate solution to about the boiling temperature of water, continuing its'application to the material from three to twenty-ton r hours according to the quality of the material being treated, and thou subjecting the liquid, together with the wood, and at the same temperature, to a heavy pressure, producing a thorough penetration of the liquid into the material under treatment.

3. The process of impregnating wood, paper, fabrics, and the like, which consists in heating a solution of boracic acid and ammonium magnesium sulfate, to a temperature of about 60 centigrade, supplying said solution to the previously-evacuated material, then raising the solution to about boiling temperature of water, permitting the same to operate on the material to be treated from three'to twenty-four hours, according to the quality of the said material, and then subjecting the solution, together with thelmaterial, while at the same temperature, to a heavy pressure, and producing a thorough penetration of the solution into the pores of the material under treatment.

In witness whereof I havehereunto set my hand in. presehce of two witnesses.

KARL RUOKER.

Witnesses: I

WOLDEMAR IIAUPT, .1 lunar I-IASPER. 

